Sound apparatus



Sept. 23, 1941'. K, DA'MEL 2,257,040

SOUND APPARATUS Filed May 3, 1938 Patented Sept. 23, 1941 UNITED STATE PATENT.

I 2,251,040 scoNn .arrsna'rcs Karl Daniel, Cologne, (Germany, assignor to "leii- Apparatebau Dr. Daniel K.-(ji., Cologne, Germany ' Application May 3, 1938, Serial No. 205,711!

x In Germany May 14, 1937 6 Claims.

This invention relates to improvements in and relating to soundapparatus and more particularly to the adjustment of the cutting depth of the cutting stylus or needle, especially in the-case of band-like sound record carriers.

Hitherto the stylus employed for recording sound according to the needle sound method was relieved of load or balanced by means of a counter-weight or a spring, whereby the required cutting depth was obtained. The more carefully and more sharplythe cutting needle or stylus was made, the more difficult was the adjustment and relieving of load of the sound box, as with a very sharp cutting needle a very slight pressure of a few grammes only suflices to produce an ample cutting depth.

Sound apparatus with such load-relieved-cutting boxes are, however, extraordinarily sensitive to the slightest disturbance, as the box is easily set in oscillation and as a consequence either too deep 2. cut is made or the cutting stylus or needle is lifted ofi the sound record carrier. Moreover,

over a long recording period, the cutting stylus or needle gradually sinks more deeply into the sound record carrier with the result that, ii thin band-t like sound record carriers are being used, they are liable to be completely perforated.

One object oi' this invention is to avoid the above disadvantage and to provide an arrangement in which the swinging of the weight or spring loaded cutting or sound box in the direcor the sound track owing to vibrations being set A still further object islto provide an arrangement which will render recording possible even in moving vehicles.

It 'will be understoodthat the invention is partlcularly suitable for use in sound app ratus where the band-like sound record carrier runs overafixedguide' path, as only in this case can a complete uniformity of the cutting depth be attained. In othersound apparatusin which the sound record carrier lies, in the cutting P 8 tion, on a rotating path, this is indeed theoreti cally, but not practically possible, as rotating bodies cannot be made to run so umiformly that small oscillations, produced by bearing-=play or the like, with consequent continual variation of the depth of out do not occur.

In order that the invention may be fully understood, I shall 'ncvvv describe one embodiment thereof, byway of example, by reierence to the accompanying diagrammatic drawing, in which:

10 Fig. 1 shows the invention in side view, and

Fig. 2 is a vertical section on the line I[--II of Fig. 1.

The cutting or sound box a is rotatably and, if necessary. axially displaceably carried on a spindle b carried on the sound apparatus. The

band-like sound record carrier is guided over a fixed guide path it under the cutting stylus or needle c. On an arm e carrying the cutting box is arranged a red I which projects with its free end beyond the spindle b so that the said spindle 11 forms a pivot point for the double-armed lever e, J. On the free end of the said rod 1 is rotatably arranged an eccentric g which is adjustable through the medium of a knob h. The eccentric y bears with its upper edge against a transverse bar 12 which is secured at one end thereof to the sound apparatus between two shoes it. A micrometer screw device 1 carried by a mountingbracket 1' secured to the frame or the sound apparatus acts on the free end of the said transverse rod i. By means of the rod f or the sound box or the eccentric 0 arranged on said rod an upward pressure isexerted ontli'e transverse bar i. The latter is, however, prevented from movin'g upwardly by the micrometer screwdeviee l.

I! the eccentric g is rotated by the knob h, the transverse bar i will not alter its position but the rod 1 and with it the sound box will be raised or lowered. If, on the other hand, the micrometer 40 screw device! is actuated, then the bar 1 is at least in part displaced upwardly or downwardly together with the eccentric 0 arranged on said rod and the rodjand sound box a. v

The method of operation of the arrangement is as follows: First the cutting stylus or needle 0 is brought into contact with the sound record carrier by rotation of the eccentric a which serves, for the coarse adjustment, and which can, it de-' sired, be replaced by any other suitable device.

Then, the fine adjustment is efiected by means of the micrometer screw device I, which adjustment can be measured byja scale.- The gauge 01 v the micrometer screw device can, in a simple manner, be arranged on the disc-like rotary head mthereot.

Iclaim;

1. An arrangement for usting the cutting depth of the cutting stylus in sound apparatus including a sound record carrier comprising the sub-combination of: a support; a double-armed lever member pivoted to said support; a sound box carrying a cutting stylus and carried by one arm of said lever member; a bar adjacent the free end 01 the other arm of said member, said bar being movably secured at one end to said support; a rotatable eccentric carried by said free arm end, said eccentric engaging said bar and serving tor coarsely adjusting said sound box; and a micrometer-like adjusting devicecarried by said support, said device engaging the free end oi said bar and serving for the fine ad- Justment of the said sound box relative to the sound record carrier.

2. An arrangement for adjusting the cutting depth of the cutting stylus in sound apparatus including a sound record carrier comprising the sub-combination of: a support, a double-armed ment toward and from the sound v record, and

lever member pivoted to said support; a sound box having a cutting stylus and carried by one arm of said lever member; means including. a part carried by the other arm of said lever member and a second part movably connected to the support for efiecting a coarse adjustment of said cutting stylus relative to the sound record carrier; and movable means carried by said support and engaged with saidsecond part and operative for effecting a me adjustment of said stylus.

3. An arrangement for adjusting the cutting depth of the cutting stylus in sound apparatus including a sound record carrier, comprising the sub-combination of: a support; a double-armed lever member pivoted to said support; a sound box having a cutting stylus carried by one arm of said lever member; a coarse adjustment device for said stylus including apart carried by the other arm of said double-armed lever-memher and a second part movably connected to the support; and a micrometer device carried bysaid depth of the cutting stylus in sound apparatus including a sound record carrier, comprising the sub-combination of a support, a sound box having a cutting stylus, means pivotally mountedon the support and holding the sound box for, movemeans'for limiting the movement; of the sound box toward the sound record including coarse adjusting means for quickly determining an approximate allowable limit of such movement and including separable partsot which one is mountedon the said pivotally-mounted means and a second part is movably aflixed to the support,

and fine adjusting means on'the support and engageable with one of said parts tor moving the same to accurately determine the exact limitation upon such movement,

5. A sound recording machine including a sup-' port having means for guiding a travelling sound carrier, a sound box mounted on the support for movement toward and from the sound carrier, a

stylus on the sound box, and meanscomprising coarse and fine adjusting devices for limiting the movement of the sound box toward the solmd carrier, said means including a stop member movably secured to the support, one of said devices including an adjustable part mounted to move bodily with the sound box for engaging said stop member and the other of said-devices.

including a part carried by the support and engageable with and eflective,for'moving the stop member.

6. A sound recording machine including a support having means for guiding a travelling sound carrier, a lever pivoted on the support, a sound box fixed on the lever and moving therewith toj ward and from the sound carrier, a stylus on the sound box, a' stop arm movably' mounted on the support, coarse adjustment means carried by support and engaged with said second part and operative for efiectinga fine adjustment'ot said the lever and engaged, with the stop arm for limiting the movement ct the sound box toward the sound carrier, and flne adjustment means carried by the support and engageable with and operative for determining the position 01' the stop arm and thereby limiting the movement of the sound box toward the sound carrier.

point of 

